VCs and angels have been throwing big money after startups and the young hotshot engineers who run them, and the tech IPO market has been hotter than any time since the late 1990s.

But established tech companies have been acting conservative, accumulating cash while their P/E ratios languish in the low double-digits -- just above the range that "steel mills trade at before they're going out of business" as Marc Andreessen recently quipped.

The last week's events make these big companies look pretty smart.

If the economy goes back into recession, having a lot of cash gives these companies a backstop if their sales collapse, helps them keep spending on R&D while poorer companies fall behind, and lets them suck up suffering competitors and startups for fractions of what they were worth a few months ago.

Here are eight U.S. tech companies sitting on more than $10 billion in cash and investments.